Method for graining explosive compositions



Patented Apr. 2, .1935' Q UNITED STATES PATENT OFFICE METHOD FOR GRAINING ExrLoslvE oomrosrrrons Willard de G. Crater, Snccasunna, N. 1., amino: to Hercules Powder Company, Wilmington,

Del., a corporation of Delaware 'No Drawing. Application January 19, 1932,

Serial No. 587,608

8 Claims. (01. 52-20) This invention relates to a method for grainwill also be found to be applicable to the producing explosive compositions and the product protion of mixtures of explosive or to an explosive duced thereby. with stabilizers and other solids in uniform,

As is well known, explosive compositions are homogeneous, free-flowing form. Thus, by way of desirably prepared for use in a free flowing form illustration, the invention will be found applicable 6 in order that they may be easily loaded. The to, for example, mixtures of nitrolactose, trinitrocapacity to flow freely is of the greatest assistance toluene and diphenylamine. As will be under- 1 in connection with explosive compositions adaptstood, this invention will be found applicable to ed, for example, for the loading of blasting caps. various mixtures of explosive compositions or to 10 Heretofore certain explosive compositions have an explosive with another solid or solids. Thus, 10 been provided in a free flowing form by crystalfor example, in the above illustration the dilization from a solution, but, as is well known, phenylamine may be replaced with, for example, many explosive compositions and especially ordiethyl diphenylurea,dimethyldiphenylurea, etc., ganic explosive compositions, have not heretofore etc. and the trinitrotoluene maybe replaced with,

been susceptible of easy preparation in a free for example, dinitrotoluene, tetryl, dinitroben- 1o flowing form due to the fact that they cannot zene, etc., etc. In the treatment of explosive combe made free-flowing by crystallization, but can positions in accordance with this invention varionly be produced in this form by costly or danous other solids may be combined with an exgerous operations, as, for example, by tumbling plosive composition or mixture of explosive comin a mixer, or, for example, spraying with a gum positions, as, for example, graphite, antimony sul- 0 solution followed by drying. fide, copper sulfide, etc.

Now, it is the'object of this invention to 'pro- In carrying out the method in accordance with vide a method whereby explosive compositions this invention, the explosive composition or mixmay be readily prepared in a free-flowing form ture of explosive compositions or mixture of ex without danger and with economy. This invenplosive composition and stabilizer or other solid 25 tion also contemplates the product of the method, to be produced in free-flowing form will be diswhich is distinguished by. its granular form, solved in a solvent or solvent mixture. Any which renders it free-flowing and hence capable suitable solvent or solvent mixture for the exof ready and eflicient loading and by the fact plosive composition or mixture to be treated and that it is dustless. which is immiscible with water, may be used. 3

The method in accordance with this invention Thus, by way of illustration, a mixture of ether will be found to be more especially adaptable to and acetone, the ether being in quantity such organic explosive compositions, which as a class that the mixture will be substantially immiscible are more generally not susceptible to crystallizawith water may be used as a solvent for lactose tion in a free-flowing form. octanitrate, tetryl, a mixture of nitrolactose, 35

The method in accordance with this invention trinitrotoluene and diphenylamine. Ethyl aceinvolves broadly the addition to water -maintate may be used as a solvent in connection with tained at anelevated temperature of a solution of the treatment of pentaerythrite tetranitrate and an explosive composition to be prepared in a free also of tetryl. Thus, it will be understood that flowing form in a solvent or mixture of solvents any solvent or solvent mixture suitable for dis- 40 which is immiscible with water. solving the explosive composition, or mixture of In accordance with this invention various exexplosive compositions, or of explosive compoplosives may be produced in a free flowing form, sitionsand other solids to be incorporated therethough, as has been indicated, the invention will with, as, for example, stabilizers and which is be found to be most advantageous in the case of substantially immiscible with water maybe used. 45 those explosive compositions, more especially or- As has been indicated, a solution of the exganic explosive compositions, which resist crystalplosive composition or mixture, etc. to be prolization in a free-flowing form. duced in a free-flowing form will be added to Thus, by way of illustration, the method in acwater maintained at an elevated temperature.

cordance with this invention, will be found to be The temperature of the water may vary widely, 50 applicable to, for example, nitrolactose, as lacdepending upon the particular solvent or solvent tose octanitrate, pentaerythrite nitrate, as penmixture used, the purpose of an elevated temtaerythrite tetranitrate, tetranitromethylamine or perature being to eliminate the solvent upon the tetryl nitrotoluene as trinitrotoluene. addition of the solution to the water. Thus, by

5 The method in accordance with this invention way of illustration, the temperature of the water may be within say, for example, the range 50-85 C., it being understood, of course, that temperatures outside of such range may be used where the character of the solvent or solvent mixture used is such that it will be eliminated at a temperature outside of such range.

The method in accordance with this invention may be carried out without the use of any special form of apparatus. However, by way of example, the invention may be desirably carried out in a closed kettle jacketed for a heating medium and equipped with a bottom outlet and a stirrer or agitating device the speed of which may be controlled. The kettle will desirably be provided with a condenser for recovery of solvent or solvent mixture and with an inlet for addition of the solution, the inlet being desirably provided with a valve enabling regulation of the admission of the solution. I

As illustrative of the practical adaptation of the method embodying this invention, for example, 1000 grams of lactose octanitrate are completely dissolved ina mixture of 2500 cc. of ether and 200 cc. of acetone. The solution will desirably be filtered to remove any foreign substances and then will be added slowly to 3 liters of water heated to a temperature of say about 55 C. with rapid stirring. The temperature is maintained and the stirring is continued until the solvent mixture ceases to come olf. As the solvent goes oil. the nitrolactose will be precipitated in the form of grains and when the solvent ceases to come oil the water may be cooled to harden the grains of nitrolactose. The nitrolactose is then separated from the water and dried in any suitable manner. The dried material will be in the form of grains of substantially uniform size and will be free flowing and dust free.

As illustrative of the granular form of the nitrolactose treated in accordance with the above illustration and as indicative of its free flowing condition reference is made to the following screen test of the product:

Percent Held on 20 mesh 5.28 Held on 30 mesh 29.25 Held on 40 mesh 35.50 Held on 50 mesh 10.90 Held on 60 mesh 7.75 Passing 60 mesh 11.32

As a further illustration-for example, 25 grams of tetryl are dissolved in 300 cc. of ether and 75 cc. of acetone. The solution is filtered to remove foreign substances if necessary and then added slowly with agitation to a body of water maintained at a temperature of say about 60 C. The temperature is maintained and the stirring continued until the solvent mixture is evaporated off and the water is then cooled to harden the grains of tetryl. The grains are separated from the water and after suitable drying will be found free-flowing and dust proof. Alternatively, 25 grams of tetryl may be dissolved in 200 cc. of ethyl acetate and run into water maintained at a temperature of 80-85 C. with agitation, the granular tetryl being separated from the water, cooled and then dried in any suitable manner. As a further illustration, for example, 25 grams of pentaerythrite tetranitrate are dissolved in 250 cc. of ethyl acetate and the solution run into water maintained at a temperature of say 80-82 C., the water being cooled after the solvent is evaporated oil to harden the grains and the granular material being separated from the water and treated as above described.

As a further illustration, 50 grams of trinitrotoluene dissolved in a mixture of 300 cc. of ether and 100 cc. of acetone may be given a granular, free-flowing form by running into water maintained at a temperature of about 60 C., the water being cooled after the solvent is evaporated ofiand the granular material is separated and dried as described.

As illustrative of the application of this invention to mixtures, for example, 950 grams of nitrolactose, 50 grams of trinitrotoluene, 7.5 grams of diphenylamine and 10 grams of graphite are added to a mixture of 2500 cc. of ether and 200 cc. of acetone. All but the graphite will be dis solved in the solvent mixture, the graphite remaining in suspension. The solution formed containing the graphite in suspension is added to 3 liters of water at about 55 C. The mixture of explosive compositions (nitrolactose and trinitrotoluene) and the stabilizer (diphenylamine) will, on evaporation of the solvent, be precipitated in homogeneous admixture in the form of grains, with the graphite incorporated throughout the grain. After the solvent is evaporated, the water is cooled, the grained product separated from the water and dried in any desired manner.

As has been indicated, various mixtures of explosive compositions and of explosive compositions and other substances desired to be included therewith, as, for example, stabilizers or other solids, may be produced in free flowing form by the method embodying this invention.

It is understood that the method in accordance with this invention will have general application to explosive compositions, mixtures thereof and mixtures thereof with other substances being especially adaptable to the treatment of explosive compositions which resist crystallization in a free-flowing form or the crystallization of which involves danger and expense and will be found more especially adaptable to the treatment of organic explosive compositions.

It will be understood that the product of the method embodying this invention is contemplated as embodying the invention, the product as indicated being recognized by its granular form resultant from the treatment, whether the product include only a single explosive composition or a plurality of explosive compositions and an explosive composition or compositions with another substance, as, for example, a stabilizer, homogeneously combined.

It will be understood that in carrying out the method in accordance with this invention various solvents and temperatures, depending upon the solvent, may be used for the treatment of various explosive compositions, the solvents, temperatures, etc., etc. given in connection with the above description and illustrations of the practice of the method being merely for purposes of illustration.

It will be understood that where in the claims appended hereto the term solvent is used, it is intended to include solvent mixtures as equivalents.

What I claim and desire to protect by Letters Patent is:

l. The method of graining a crystalline organic explosive compound which includes 'dissolving the explosive compound in a solvent which is substantially immiscible with water and evaporating the solvent in the presence of water sive mixture in a solvent which is substantially heated to a temperature at which the solvent 7 will be evaporated.

2. The method of graining a crystalline organic explosive compound which includes dissolving the explosive compound in a solvent which is substantially immiscible with waterand introducing the solution into a body of water heated to a temperature at which the solvent will be evaporated while agitating the body of water.

3. The method of graining a crystalline organic explosive compound which includes dissolving the explosive compound in a solvent which is substantially immiscible with water and which will boil at a temperature within the range 50-85 C. and introducing the solution into a body of water heated to a temperature within the range 50-85" C.

4. The method oi graining a crystalline .organic explosive compound which includes dissolving the explosive compound in a solvent which is substantially immiscible with water, introducing the solution into a body of water heated to a temperature at which the solvent will be evaporated, separating the precipitated explosive compound from the water and drying the explosive compound.

5. The method 0! graining an explosive mix ture containing a crystalline organic explosive compound which includes dissolving the exploimmiscible with water and introducing the solution into a body of water heated to a temperature at which the solvent will be evaporated.

6. The method of graining nitrolactose which includes dissolving nitrolactose in a solvent which is substantially immiscible with water,-

introducing the solution into water heated to a temperature at which the solvent will be evaporated, separating the precipitated nitrolactose from the water and drying the nitrolactose.

'1. The method 01' graining a crystalline organic explosive compound and a substance to be incorporated therewith which includes dissolving the explosive compound and the substance to be incorporated therewith in a solvent therefor which is substantially immiscible with water and introducing the solution into a body of water heated to a temperature at which the solvent will be evaporated.

8. The method of graining a crystalline organic explosive compound and a stabilizer which includes dissolving the explosive compound and the stabilizer in a solvent therefor which is substantially immiscible with water and introducing the solution into a body of water heated to a temperature at which the solvent will be evaporated.

WILLARD n: C. CRATER. 

